Cement compositions comprising biodegradable monomers for retarding the setting thereof

ABSTRACT

Cement compositions may comprise one or more secondary amines substituted with a carboxyl group or salts thereof (e.g., 3-hydroxy N,N′-iminodisuccinic acid) for retarding the setting of such compositions. The inclusion of such materials in cement compositions may be highly beneficial. In wellbores having BHCT&#39;s of less than or equal to about 250° F., the use of the secondary amine as the set retarder ensures that the thickening time of the cement composition is sufficient to allow the cement composition to be pumped to its desired downhole location. Further, the secondary amine may be used in combination with conventional set retarders to enhance the ability of those retarders to increase the thickening time of the cement composition at higher BHCT&#39;s, e.g., from about 250° F. to about 525° F.

FIELD OF THE INVENTION

The present invention generally relates to cementing, and moreparticularly to cement compositions comprising certain monomers (i.e.,biodegradable secondary amines substituted with carboxyl groups or saltsthereof), copolymers thereof, terpolymers thereof, and/or block polymersthereof for retarding the setting of the compositions.

BACKGROUND AND SUMMARY OF THE INVENTION

The following paragraphs contain some discussion, which is illuminatedby the innovations disclosed in this application, and any discussion ofactual or proposed or possible approaches in this Background sectiondoes not imply that those approaches are prior art.

Natural resources such as oil and gas residing in a subterraneanformation or zone are usually recovered by drilling a wellbore down tothe subterranean formation while circulating a drilling fluid in thewellbore. After terminating the circulation of the drilling fluid, astring of pipe, e.g., casing is run in the wellbore. The drilling fluidis then usually circulated downwardly through the interior of the pipeand upwardly through the annulus, which is located between the exteriorof the pipe and the walls of the wellbore. Next, primary cementing istypically performed whereby a cement slurry is placed in the annulus andpermitted to set into a hard mass (i.e., sheath) to thereby attach thestring of pipe to the walls of the wellbore and seal the annulus.Subsequent secondary cementing operations may also be performed. Oneexample of a secondary cementing operation is squeeze cementing wherebya cement slurry is employed to plug and seal off undesirable flowpassages in the cement sheath and/or the casing.

These cementing operations generally occur in a wide variety ofwellbores ranging, for example, from shallow wells of less than about1,000 feet to extremely deep wells of greater than about 35,000 feet.The cement composition desirably remains in a pumpable state until ithas been placed at its desired location in the wellbore, for example, inthe annulus. However, the thickening time of the composition may beunacceptably short to allow it to be pumped to its desired downholelocation. As a result, the cement slurry may set in an undesirablelocation such as inside the casing, which may lead to expensive drillout operations. Set retarders have typically been included in cementcompositions to lengthen the thickening times thereof and thereby delaythe setting of the compositions until after placement. Some setretarders that are commonly used in cement compositions includelignosulfonates, hydroxycarboxy acids, phosphonic acid derivatives,synthetic polymers (e.g., copolymers of 2-acrylamido-2-methylpropanesulfonic acid (AMPS)), borate salts, and combinations thereof.

Often the temperatures in a wellbore increase from the top down to thebottom of the wellbore. Unfortunately, increasing the temperature of acement composition results in a decrease in the thickening time of thecomposition. Thus, in wellbores having bottom hole circulatingtemperatures (BHCT) above about 350° F., conventional set retarderscommonly fail to sufficiently lengthen the thickening times of cementcompositions to allow those compositions to be pumped to their desireddownhole locations. Therefore, the use of such set retarders limits thedepths and associated temperatures at which wellbores may be drilled andisolated with cement compositions.

To overcome such limitations, traditional set retarders have beensupplemented with ethylenediamine tetra acetic acid (EDTA) or its sodium(Na) salt to intensify their retardation effect on the setting of cementcompositions at higher temperatures. The combination of the traditionalset retarders with the EDTA or its Na salt typically provides fordesirable levels of set retardation in cement compositions subjected toBHCT's as high as 525° F. or even higher. However, EDTA and its Na saltsuffer from the drawback of being toxic and having a relatively lowbiodegradability, i.e., its susceptibility to breakdown bymicroorganisms. As such, their use is often limited to lowconcentrations or even restricted entirely in places such as the UnitedKingdom and the North Sea where strict environmental regulations apply.Further, EDTA and its Na salt are costly to produce. It is thereforedesirable to develop a less expensive set retarder composition that isnon-toxic and exhibits a relatively high biodegradability.

Additional information relating to conventional set retarders may befound in U.S. patent application Ser. Nos. 10/963,036 and 10/963,035,filed on Oct. 11, 2004, each of which is incorporated herein byreference.

Some teachings and advantages found in the present application aresummarized briefly below. However, note that the present application maydisclose multiple embodiments, and not all of the statements in thissection necessarily relate to all of those embodiments. Moreover, noneof these statements limit the claims in any way.

According to various embodiments, one or more secondary aminessubstituted with a carboxyl group or salts thereof (e.g., 3-hydroxyN,N′-iminodisuccinic acid) may be included in cement compositions forretarding the setting of such compositions. As used herein,“secondaryamines substituted with a carboxyl group” not only refers to the aminesthemselves but also refers to copolymers thereof, terpolymers thereof,block polymers thereof, or any combination thereof. The inclusion ofsuch materials in cement compositions may be highly beneficial. Inwellbores having bottom hole circulating temperatures (BHCT's) of lessthan or equal to about 250° F., the use of the secondary amine as theset retarder ensures that the thickening time of the cement compositionis sufficient to allow the cement composition to be pumped to itsdesired downhole location. Further, the secondary amine may be used incombination with conventional set retarders to enhance the ability ofthose retarders to increase the thickening time of the cementcomposition at higher BHCT's, e.g., from about 250° F. to about 525° F.

In addition, such secondary amines substituted with a carboxyl group orsalts thereof exhibit relatively low levels of toxicity and relativelyhigh biodegradability percentages (e.g., greater than 60%). Thus, theymay be employed in cement compositions without being concerned that theycould harm the environment. Advantageously, they can be used in placesthat have strict requirements on the levels of toxicity andbiodegradability. In addition, the secondary amines may be produced atrelatively low cost. As such, their inclusion in cement compositionswould not prohibitively raise the cost of producing such compositions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a graph illustrating the biodegradability of 3-hydroxyN,N′-iminodisuccinic acid over a period of 28 days.

FIG. 2 depicts a side plan view of a drill rig and a wellbore forrecovering oil or gas from a subterranean formation penetrated by thewellbore.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Cement compositions include cement, a fluid, and a set retardercomposition for increasing the thickening time of the compositions andthus delaying the setting thereof. In some embodiments, the set retardercomposition primarily comprises a secondary amine substituted with acarboxyl group, particularly when it may be exposed to temperatures lessthan or equal to about 250° F. In these embodiments, the secondary aminemay be capable of increasing the thickening time of the cementcomposition to a time in the range of from about 3 hours to about 8hours. In alternative embodiments, the set retarder composition maycomprise a conventional set retarder and a secondary amine substitutedwith a carboxyl group for enhancing the ability of the conventional setretarder to increase the thickening time of the cement compositions,particularly when it may be exposed to temperatures in a range of fromabout 250° F. to about 525° F. In these embodiments, the secondary aminemay be capable of increasing the thickening time to a time in the rangeof from about 3 hours to about 8 hours, alternatively from about 4 hoursto about 5 hours.

The secondary amine substituted with the carboxyl group desirablyexhibits a high biodegradability and a low toxicity, allowing it to beemployed in places where strict environmental regulations apply such asthe North Sea and the United Kingdom. It may exhibit a biodegradabilityover a period of 28 days of greater than about 60% biological oxygendemand (BOD). In this application, the standard test applied todetermine biodegradability is OECD (Organisation for EconomicCo-operation and Development) Guidelines for the Testing of Chemicals,Test No. 302C: Inherent Biodegradability: Modified MITI Test (II).Further, according to a standard fish toxicity test, the secondary aminemay have a 96-hour LC₅₀ of greater than about 2,000 ppm, indicating thatit is not toxic to fish (in the U.S., chemicals having a LC₅₀<1.0 ppmare labeled toxic to fish). Examples of suitable secondary aminessubstituted with carboxyl groups include but are not limited to thefollowing monomers: ethylenediamine-N,N′-disuccinic acid (EDDS) or saltsthereof; carboxymethylaspartic acid (CMAA) or salts thereof;carboxyethylaspartic acid (CEAA) or salts thereof; iminodiacetic acid(IDA) or salts thereof; iminodisuccinic acid (IDS) or salts thereof;methylglycinedisuccinic acid (MGDS) or salts thereof; 3-hydroxyN,N′-iminodisuccinic acid (HIDS) or salts thereof; and combinationsthereof. Additional examples include polymers made up of any combinationof the foregoing monomers including copolymers thereof, terpolymersthereof, block polymers thereof, and combinations thereof. The carboxylgroup substituent may be, for example, —COOH, —COONa, —COOK, —COOLi, orCOONH₄. The foregoing monomers and polymers thereof not only serve asgood set retarders or set retarder intensifiers, they also serve as goodcement dispersants in the cement compositions.

FIG. 1 is a graph of the degradation of HIDS as a function of time. Itillustrates that the degradation of HIDS increased to more than 60% BODafter a period of about 13 days and then increased to about 80% BODafter a total period of about 28 days. Thus, HIDS is a veryenvironmentally friendly amine, making it a good candidate for use incement compositions.

The secondary amine substituted with a carboxyl group may be present incement compositions in an amount sufficient to provide the desired levelof set retardation, which may be based on a number of factors includingthe desired thickening time of the compositions, the bottom holecirculating temperature (BHCT) and the bottom hole pressure of thewellbore in which the compositions are to be placed, and the amount, ifany, of conventional set retarder present in the compositions. Higherconcentrations of the secondary amine may be needed with increasingBHCT. In various embodiments, the amount of the secondary aminesubstituted with the carboxyl group present in the cement compositionsmay be in the range of from about 0.001% to about 10% by weight of thecement (bwoc), or alternatively in the range of from about 0.1% to about5% bwoc.

As mentioned previously, in some embodiments, the secondary aminesubstituted with the carboxyl group may be used in conjunction with aconventional set retarder. Any suitable conventional set retarder asdeemed appropriate by one skilled in the art may be utilized. Examplesof suitable conventional set retarders include but are not limited tolignosulphonate, commercially available from Halliburton EnergyServices, Inc. under the tradename of HR-5L retarder, lignosulfates,hydroxycarboxy acids, phosphonic acid derivatives, borate salts, andcombinations thereof. Examples of hydroxycarboxy acids include tartaricacid, commercially available from Halliburton Energy Services, Inc.under the tradename of HR-25 retarder, gluconic acid, citric acid,gluconoheptanoic acid, and combinations thereof. An example of a setretarder additive comprising a phosphonic acid derivative is MIRCROMATRIX CEMENT RETARDER additive, which is sold by Halliburton EnergyServices, Inc. and described in U.S. Pat. Nos. 5,340,397 and 5,484,478,each of which is incorporated by reference herein in its entirety.Examples of borate salts include potassium pentaborate, sodiumtetraborate, borax, and combinations thereof. A suitable borate salt iscommercially available from Halliburton Energy Services, Inc. under thetradename of COMPONENT R retarder. Examples of synthetic polymersinclude copolymers of olefinically unsaturated non-acrylate sulfonatemonomers and olefinically unsaturated carboxylic acid monomers, e.g., acopolymer of styrene sulfonic acid and maleic anhydride, which aredescribed in U.S. patent application Ser. No. 10/963,036, filed on Oct.11, 2004, entitled“Methods of Cementing in Subterranean Formations.”Another suitable synthetic polymer is SCR-100 retarder, which is sold byHalliburton Energy Services, Inc. and described in U.S. Pat. Nos.4,941,536, 5,049,288, and 5,472,051, each of which is incorporated byreference herein in its entirety. Yet another suitable synthetic polymeris SCR-500 retarder, which is sold by Halliburton Energy Services, Inc.and described in U.S. Pat. No. 5,536,311, also incorporated by referenceherein in its entirety.

The amount of the conventional retarder present in the cementcompositions may be based on a number of factors including the desiredthickening time of the compositions, the bottom hole circulatingtemperature (BHCT) and the bottom hole pressure of the wellbore in whichthe compositions are to be placed, and the amount and type of thesecondary amine substituted with the carboxyl group present in thecompositions. Higher concentrations of the conventional retarder may beneeded with increasing BHCT. In various embodiments, the amount of theconventional retarder present in the cement compositions may be lessthan or equal to about 10% bwoc, or alternatively less than or equal toabout 5% bwoc. In some embodiments, a weight ratio of the secondaryamine substituted with the carboxyl group to the conventional primaryretarder may range from about 1:0 to about 1:50.

Cements deemed appropriate by one skilled in the art may be employed inthe cement compositions. For example, the cement may be a hydrauliccement composed of calcium, aluminum, silicon, oxygen, and/or sulfurwhich sets and hardens by reaction with water. Examples of hydrauliccements include but are not limited to Portland cements, pozzolancements, gypsum cements, high alumina content cements, silica cements,and high alkalinity cements. In some embodiments, the cement may be aclass A, B, C, G, or H Portland cement. The cement compositions may alsoinclude a sufficient amount of fluid to form a pumpable cementitiousslurry. Examples of suitable fluids include but are not limited to freshwater or salt water, e.g., an unsaturated aqueous salt solution or asaturated aqueous salt solution such as brine or seawater. In someembodiments, the water may be present in the cement compositions in anamount in the range of from about 33% to about 200% bwoc, alternativelyfrom about 35% to about 60% bwoc.

In various embodiments, the cement compositions also include a suitablestrength-retrogression additive as deemed appropriate by one skilled inthe art. As used herein, “strength-retrogression additive” refers tomaterials that are capable of preventing the strength retrogression of aset cement composition when exposed to high temperatures. Examples ofsuitable strength-retrogression additives include but are not limited tocrystalline silica such as coarse grain crystalline silica, fine graincrystalline silica, and combinations thereof. An example of a suitablefine grain crystalline silica is SSA-1 additive, commercially availablefrom Halliburton Energy Services, Inc. An example of a suitable coursegrain crystalline silica is SSA-2 additive, also commercially availablefrom Halliburton Energy Services, Inc. The amount of thestrength-retrogression additive present in the cement compositions maybe selected to provide the desired level of strength retrogressionprevention. In some embodiments, the amount of thestrength-retrogression additive present may be in the range of fromabout 10% to about 100% bwoc.

As deemed appropriate by one skilled in the art, additional additivesmay be added to the cement compositions for improving or changing theproperties of the cement compositions. Examples of such additivesinclude but are not limited to fluid loss control additives, de-foamers,dispersing agents, set accelerators, and formation conditioning agents.Another example of a suitable additive is a density reducing additivesuch as hollow glass beads, hollow cenospheres, and the like.

The foregoing cement compositions may be prepared using any suitabletechnique known in the art. The various components in the cementcompositions may be combined in any suitable order. In some embodiments,particularly when the amine substituted with the carboxyl group is asolid, it may be dry blended with the cement and other dry additiveseither on-site near where it is to be used or off-site, in which casethe dry blend may be transported to the on-site location. In otherembodiments, particularly when the amine substituted with the carboxylgroup is a liquid, it may be added to the mix water used to make thecement composition.

FIG. 2 illustrates using a cement composition comprising the setretarder composition described herein. An oil rig 40 may be positionednear the surface of the earth 42 for later recovering oil from asubterranean formation (not shown). A wellbore 44 may be drilled in theearth such that it penetrates the subterranean formation. A pipe 52,e.g., a casing, may extend down through wellbore 44 for delivering fluidto and/or from the wellbore. In a primary cementing process, the cementcomposition may be pumped down through pipe 52 and up through theannulus of wellbore 44 as indicated by arrows 46 using one or more pumps54. The cement composition may be allowed to set within the annulus,thereby sealing wellbore 44. Due to the presence of the set retardercomposition in the cement composition, the thickening time of the cementcomposition is desirably sufficient to allow it to be pumped into theannulus such that it substantially fills the annulus before setting. Anysecondary cementing operations known in the art may also be performedusing the cement composition. For example, a squeeze cementing techniquemay be employed to plug permeable areas or voids in the cement sheath orthe pipe 52. Again, the thickening time of the cement composition issufficient to ensure that the cement composition remains pumpable untilit has been placed in its desired location. By way of example, theBHCT's of wellbore 44 may be in the range of from about 150° F. to about525° F., and the resulting thickening time of the cement composition mayrange from about 3 hours to about 8 hours.

EXAMPLES

The invention having been generally described, the following examplesare given as particular embodiments of the invention and to demonstratethe practice and advantages thereof. It is understood that the examplesare given by way of illustration and are not intended to limit thespecification or the claims to follow in any manner.

Various samples of cement slurries were prepared and tested forthickening times according to API Recommended Practice for Testing WellCements 10B, 23^(rd) edition, April 2002. Each test sample containedclass H cement, 35% bwoc of SSA-1 strength-retrogression additive, asufficient amount of water to form a slurry having a density of 16.2pounds per gallon, and different amounts of HIDS and/or HR-25 retarder,as shown in Table 1 below. The thickening times were tested using a HPHT(high pressure-high temperature) consistometer. The thickening timesobtained for each sample at different temperatures are also given inTable 1.

TABLE 1 Thickening Thickening Thickening HR-25 Time @ Time @ Time @Sample HIDS, retarder, 250° F., 300° F., 350° F., No. % bwoc % bwochr.:min. hr.:min. hr.:min. 1 1.0 0 8:00 1:27 2 1.0 0.25 7:18 3 1.0 0.53:55

The results in Table 1 show that HIDS is an extremely good retarder byitself up to about 250° F. Further, HIDS works well to intensify theeffect of other retarders such as HR-25 retarder up to at least 350° F.These examples are desirably extended life slurries having shelf livesup to 3 to 4 weeks.

According to various embodiments, methods of cementing in a wellborecomprise: introducing a cement composition comprising a secondary aminesubstituted with a carboxyl group into the wellbore; and allowing thecement composition to set. In yet more embodiments, methods of cementingin a wellbore comprise: preparing a cement composition by combiningcement, water, and a secondary amine substituted with a carboxyl group;displacing the cement composition into the wellbore; and allowing thecement composition to set.

In more embodiments, cement compositions comprise: a secondary aminesubstituted with a carboxyl group for retarding a set time of the cementcomposition. In further embodiments, cement compositions comprise: acement; a strength-retrogression additive; water for making cementcomposition pumpable; a primary retarder for increasing a thickeningtime of the cement composition; and a secondary amine substituted with acarboxyl group for enhancing the ability of the primary retarder toincrease a thickening time of the cement composition. In additionalembodiments, set retarder compositions for use as additives in cementcompositions comprise a secondary amine substituted with a carboxylgroup.

MODIFICATIONS AND VARIATIONS

The foregoing methods of cementing a wellbore may be applied to varioustypes of wells, including injection wells, single production wells suchas oil and gas wells, and multiple completion wells.

While preferred embodiments of the invention have been shown anddescribed, modifications thereof can be made by one skilled in the artwithout departing from the spirit and teachings of the invention. Theembodiments described herein are exemplary only, and are not intended tobe limiting. Many variations and modifications of the inventiondisclosed herein are possible and are within the scope of the invention.

Accordingly, the scope of protection is not limited by the descriptionset out above but is only limited by the claims which follow, that scopeincluding all equivalents of the subject matter of the claims. Each andevery claim is incorporated into the specification as an embodiment ofthe present invention. Thus, the claims are a further description andare an addition to the preferred embodiments of the present invention.The discussion of a reference herein is not an admission that it isprior art to the present invention, especially any reference that mayhave a publication date after the priority date of this application. Thedisclosures of all patents, patent applications, and publications citedherein are hereby incorporated by reference, to the extent that theyprovide exemplary, procedural, or other details supplementary to thoseset forth herein.

1. A cement composition comprising: a secondary amine substituted with acarboxyl group for retarding a set time of the cement composition,wherein the secondary amine substituted with a carboxyl group comprisesat least one secondary amine substitute with a carboxyl group selectedfrom the group consisting of: an ethylenediamine-N,N′-disuccinic acid, asalt of an ethylenediamine-N,N′-disuccinic acid, a carboxymethylasparticacid, a salt of a carboxymethylaspartic acid, an iminodisuccinic acid, asalt of an iminodisuccinic acid, a methylglycinedisuccinic acid, a saltof a methylglycinedisuccinic acid, a 3-hydroxy N,N′iminodisuccinic acid,a salt of a 3-hydroxy N,N′-iminodisuccinic acid, copolymers thereof,terpolymers thereof, block polymers thereof, and combinations thereof.2. The cement composition of claim 1, having a thickening time in arange of from about 3 hours to about 8 hours when exposed to atemperature of less than or equal to about 250° F.
 3. The cementcomposition of claim 1, further comprising a primary retarder forincreasing the thickening time of the cement composition.
 4. The cementcomposition of claim 3, wherein the secondary amine substituted with thecarboxyl group is capable of enhancing the ability of the primaryretarder to increase the thickening time of the cement composition. 5.The cement composition of claim 4, having a thickening time in a rangeof from about 3 hours to about 8 hours when exposed to a temperature ina range of from about 250° F. to about 525° F.
 6. The cement compositionof claim 4, having a thickening time in a range of from about 4 hours toabout 5 hours when exposed to a temperature in a range of from about250° F. to about 525° F.
 7. The cement composition of claim 3, whereinthe primary retarder comprises lignosulphonate, hydroxycarboxy acid orsalts thereof, a phosphonic acid derivative, a borate salt, a copolymerof an olefinically unsaturated non-acrylate sulfonate monomer and anolefinically unsaturated carboxylic acid monomer, and combinationsthereof.
 8. The cement composition of claim 3, wherein the primaryretarder comprises at least one primary retarder selected from the groupconsisting of: a tartaric acid, a gluconic acid, a citric acid, agluconoheptanoic acid, and combinations thereof.
 9. The cementcomposition of claim 3, wherein an amount of the primary retarderpresent in the cement composition is less than or equal to about 10%bwoc.
 10. The cement composition of claim 3, wherein a weight ratio ofthe secondary amine substituted with the carboxyl group to the primaryretarder is in a range of from about 1:0 to about 1:50.
 11. The cementcomposition of claim 1, wherein the secondary amine substituted with acarboxyl group has a biodegradability of greater than or equal to about60%.
 12. The cement composition of claim 1, wherein the secondary aminesubstituted with the carboxyl group comprises 3-hydroxyN,N′-iminodisuccinic acid.
 13. The cement composition of claim 12,wherein the secondary amine substituted with the carboxyl group has abiodegradability of greater than or equal to about 60% BOD after aperiod of about 13 days and of greater than about 80% BOD after a periodof about 28 days.
 14. The cement composition of claim 1, wherein thesecondary amine substituted with the carboxyl group has a 96 hour LC₅₀of greater than about 2,000 ppm.
 15. The cement composition of claim 1,wherein a concentration of the secondary amine substituted with thecarboxyl group is in a range of from about 0.001% to about 10% by weightof the cement composition.
 16. The cement composition of claim 1,further comprising water present in an amount ranging from about 33% toabout 200% bwoc.
 17. The cement composition of claim 1, furthercomprising a strength-retrogression additive present in an amountranging from about 10% to about 100% bwoc.
 18. The cement composition ofclaim 1, being disposed in a wellbore penetrating a subterraneanformation.
 19. A cement composition comprising: a cement; astrength-retrogression additive; water for making the cement compositionpumpable; a primary retarder for increasing a thickening time of thecement composition; and a secondary amine substituted with a carboxylgroup for enhancing the ability of the primary retarder to increase athickening time of the cement composition, wherein the secondary aminesubstituted with the carboxyl group comprises at least one secondaryamine substituted with a carboxyl group selected from the groupconsisting of: an ethylenediamine-N,N′-disuccinic acid, a salt of anethylenediamine-N,N′-disuccinic acid, a carboxymethylaspartic acid, asalt of a carboxymethylaspartic acid, an iminodisuccinic acid, a salt ofan iminodisuccinic acid, a methylglycinedisuccinic acid, a salt of amethylglycinedisuccinic acid, a 3-hydroxy N,N′iminodisuccinic acid, asalt of a 3-hydroxy N,N′-iminodisuccinic acid, copolymers thereof,terpolymers thereof, block polymers thereof, and combinations thereof.20. The cement composition of claim 19, having a thickening time in arange of from about 3 hours to about 8 hours when subjected to atemperature of less than or equal to about 250° F.
 21. The cementcomposition of claim 19, having a thickening time in a range of fromabout 3 hours to about 8 hours when subjected to a temperature in arange of from about 250° F. to about 525° F.
 22. The cement compositionof claim 19, having a thickening time in a range of from about 4 hoursto about 5 hours when subjected to a temperature in a range of fromabout 250° F. to about 525° F.
 23. The cement composition of claim 19,wherein the primary retarder comprises at least one primary retarderselected from the group consisting of: lignosulphonate, hydroxycarboxyacid or salts thereof, a phosphonic acid derivative, a borate salt, acopolymer of an olefinically unsaturated non-acrylate sulfonate monomerand an olefinically unsaturated carboxylic acid monomer, andcombinations thereof.
 24. The cement composition of claim 19, whereinthe primary retarder comprises at least one primary retarder selectedfrom the group consisting of: a tartaric acid, a gluconic acid, a citricacid, a gluconoheptanoic acid, and combinations thereof.
 25. The cementcomposition of claim 19, wherein an amount of the primary retarderpresent in the cement composition is less than or equal to about 10%bwoc.
 26. The cement composition of claim 19, wherein a weight ratio ofthe secondary amine substituted with the carboxyl group to the primaryretarder is in a range of from about 1:0 to about 1:50.
 27. The cementcomposition of claim 19, wherein the secondary amine substituted withthe carboxyl group has a biodegradability of greater than or equal toabout 60%.
 28. The cement composition of claim 19, wherein the secondaryamine substituted with the carboxyl group comprises 3-hydroxyN,N′-iminodisuccinic acid.
 29. The cement composition of claim 28,wherein the secondary amine substituted with the carboxyl group has abiodegradability of greater than or equal to about 60% BOD after aperiod of about 13 days and of greater than about 80% BOD after a periodof about 28 days.
 30. The cement composition of claim 19, wherein thesecondary amine substituted with the carboxyl group has a 96 hour LC₅₀of greater than about 2,000 ppm.
 31. The cement composition of claim 19,wherein a concentration of the set retarder is in a range of from about0.001% to about 10% by weight of the cement composition.
 32. The cementcomposition of claim 19, wherein a concentration of the water is in arange of from about 33% to about 200% bwoc.
 33. The cement compositionof claim 19, wherein a concentration of the strength-retrogressionadditive is in a range of from about 10% to about 100% bwoc.
 34. Thecement composition of claim 19, being disposed in a wellbore penetratinga subterranean formation.
 35. A cement composition comprising: aPortland cement; water in an amount in the range of about 33% to about200% bwoc; a primary retarder for increasing a thickening time of thecement composition; and a secondary amine substituted with a carboxylgroup for enhancing the ability of the primary retarder to increase athickening time of the cement composition, wherein the secondary aminesubstituted with a carboxyl group comprises at least one secondary aminesubstitute with a carboxyl group selected from the group consisting of:an ethylenediamine-N,N′-disuccinic acid, a salt of anethylenediamine-N,N′-disuccinic acid, a carboxymethylaspartic acid, asalt of a carboxymethylaspartic acid, an iminodisuccinic acid, a salt ofan iminodisuccinic acid, a methylglycinedisuccinic acid, a salt of amethylglycinedisuccinic acid, a 3-hydroxy N,N′iminodisuccinic acid, asalt of a 3-hydroxy N,N′-iminodisuccinic acid, copolymers thereof,terpolymers thereof, block polymers thereof, and combinations thereof.36. The cement composition of claim 35, having a thickening time in arange of from about 3 hours to about 8 hours when subjected to atemperature of less than or equal to about 250° F.
 37. The cementcomposition of claim 35, having a thickening time in a range of fromabout 3 hours to about 8 hours when subjected to a temperature in arange of from about 250° F. to about 525° F.
 38. The cement compositionof claim 35, having a thickening time in a range of from about 4 hoursto about 5 hours when subjected to a temperature in a range of fromabout 250° F. to about 525° F.
 39. The cement composition of claim 35,wherein the primary retarder comprises at least one primary retarderselected from the group consisting of: lignosulphonate, hydroxycarboxyacid or salts thereof, a phosphonic acid derivative, a borate salt, acopolymer of an olefinically unsaturated non-acrylate sulfonate monomerand an olefinically unsaturated carboxylic acid monomer, andcombinations thereof.
 40. The cement composition of claim 35, whereinthe primary retarder comprises at least one primary retarder selectedfrom the group consisting of: a tartaric acid, a gluconic acid, a citricacid, a gluconoheptanoic acid, and combinations thereof.
 41. The cementcomposition of claim 35, wherein an amount of the primary retarderpresent in the cement composition is less than or equal to about 10%bwoc.
 42. The cement composition of claim 35, wherein a weight ratio ofthe secondary amine substituted with the carboxyl group to the primaryretarder is in a range of from about 1:0 to about 1:50.
 43. The cementcomposition of claim 35, wherein the secondary amine substituted withthe carboxyl group has a biodegradability of greater than or equal toabout 60%.
 44. The cement composition of claim 35, wherein the secondaryamine substituted with the carboxyl group comprises 3-hydroxyN,N′-iminodisuccinic acid.
 45. The cement composition of claim 44,wherein the secondary amine substituted with the carboxyl group has abiodegradability of greater than or equal to about 60% BOD after aperiod of about 13 days and of greater than about 80% BOD after a periodof about 28 days.
 46. The cement composition of claim 35, wherein thesecondary amine substituted with the carboxyl group has a 96 hour LC₅₀of greater than about 2,000 ppm.
 47. The cement composition of claim 35,wherein a concentration of the secondary amine substituted with thecarboxyl group is in a range of from about 0.001% to about 10% by weightof the cement composition.